Valve gear for engines



Dec. 2, 1941. A. TEBALDI VALVE GEAR FOR ENGINES Filed April 26, 1959 Fig. 1

lN-VENTOR 'ALESSANDfO, T EBALDI ATTYS.

Patented Dec. 2, 1941 VALVE GEAR FOR ENGINES Alessandro Tebaldi, Milan, ltaly, assignor of onehalf to Fabbrica Automobili Isotta Fraschini, Milan, Italy, a corporation of Italy Application April 26, 1939, Serial No. 270,229 In Italy May 21, 1938 4 Claims.

This invention relates to valve actuating gears in engines with cam operated valves in which an oscillating arm or tappet is located intermediate each cam and the stem of the respective valve to impart the cam action to said valve without developing transverse stresses thereon.

In the gears of the above stated class the adjustment of the dead space or gap in the gear is made by adjusting the thickness of a shim inserted intermediate the end of the valve stem and a cap located on the same and acted on by said oscillating arm; such adjustment requires said arm to be removed in order to insert or change shims intermediate the valve stem and cap.

This invention is directed to an arrangement in which the troubles inherent to said operation are removed because each oscillating arm operative intermediate a valve stem and the respective cam is mounted on its spindle with a freedom for being displaced laterally and removable means are provided to hold it in its operative position.

It is thereby made possible to shift laterally said arm when required to expose the end of the cooperating valve stem in order to remove and locate the cap with the adjusting shim therefrom and thereon, and subsequently again engage said arm in its position for cooperation with the respective'cam and valve.

An embodiment of this invention is shown by way of example on the annexed drawing and Fig. 1 is a fragmentary transverse section of a portion of a head of an explosion engine in which the present invention is embodied;

Fig. 2 shows diagrammatically in side view with parts in section, the cooperation of a cam, a valve stem and an intermediate oscillating arm;

Fig. 3 is a fragmentary plan view of a portion of an engine head with actuating means according to this invention for two adjacent valves;

Fig. 4 is a plan view similar to Fig. 3 with one of said oscillating arms in a transversely shifted position, and

Fig. 5 is a transverse section on 5-5, Fig. 3, with parts removed.

In Fig. 1, l denotes the engine head where the valves are mounted one of said valves bein shown diagrammatically by its stem 2, and 3 is a cam shaft having a cam 4 in register with the valve stem 2. The free end of an arm 5 loose on a spindle 6 is located intermediate each cam 4 and the end of the cooperating valve stem 2.

diverging ends as H".

As shown in Fig. 2, a cap I is located over the end of the stem 2; the actual extension of the cap 1 above the end of the valve stem 2 may be adjusted by means of shims as 8 located within said cap I in order to adjust the gap intermediate the cooperating surfaces of the cam 4 and arm 5.

In accordance with this invention each arm 5 is pivotally mounted on the engine head by means providing for shifting it laterally and it is held in its normal operative position by at least an appropriate engaging member adapted to be easily released.

In the illustrated embodiment the arms 5 cooperating with two adjacent valves are loose on a single spindle 6, each of said arms 5 having a hub 9 free to oscillate about and to move along said spindle 6; said hubs 9, 9 of said arms have in their whole an extent in the direction of the axis of the spindle B which is shorter than the distance intermediate the stems 2 of the coop erating valves, said hubs being confined in their normal operative position by means of a removable spacer which holds the two hubs 9 at a distance from each other.

In the illustrated construction said spacer consists of a split member located on the spindie 6 intermediate the hubs 9 of the two adjacent arms 5 and more particularly it consists of a sleeve I0 divided in two sections and held assembled over the spindle 6 say by means of a resilient clip ll.

When the sleeve I0 is assembled on the spindle 6 intermediate the hubs 9 and is engaged by the clip II as illustrated in Fig. 3, the two arms 5 may oscillate around the spindle 5 for normal operation but are restricted from moving along it.

On the contrary when the split sleeve I0 is I removed from the spindle 6 after the clip II removed, each of said arms 5 is released in register with one 01 its sides and accordingly either of them may be moved laterally along the spindle B as shown in Fig. 4; the end of the stem 2 of the cooperating valve is thus left clear and the associate cap 1 may be removed to manipulate the shim 8 located intermediate it and the top of the stem 2.

The sleeve sections III are preferably connected with the clip I I say in the manner shown in Fig. 5 where the limbs of said clip extend in grooves III of the sections [0 and are engaged with them by means of rivets l2, and preferably said clip provides an outer loop as H and extending and The spacer I0, ll thus provides a unitary member which may be removed from the spindle 6 by exerting a pull on the loop ii the sleeve sections I 0 being thus caused to move ofl. from each other; on the other hand the said spacer I0, I I may be easily located over the spindle 6 when required to engage the hubs 9 and arms 5 in their operative position by forcing the diverging limbs ll" of the clip ll against the cylindrical spindle 6 which causes said limbs and the sleeve sections I II, I to recede from each other said parts finally snapping on the spindle 6 in assembled position,

What I claim as my invention and desire to secure by United States Letters Patent is:

1. In a valve actuating gear including an actuated member, an actuating member and a rocker arm having a hub portion and a contact portion adapted to be normally located intermediate the actuated and actuating members, a mounting for said rocker arm comprising a spindle on which said rocker arm hub portion is mounted for rocking movement and also for lateral movement along the axis of said spindle, and means on said spindle for preventing said lateral movement of said rocker arm, said means engaging said spindle and being removable in a direction transverse to said spindle.

2. In a valve actuating gear including an actuated member, an actuating member and a rocker arm having a hub portion and a contact portion adapted to be normally located intermediate the actuated and actuating members, a mounting for said rocker arm comprising a spindle on which said rocker arm hub portion is mounted for rocking movement and also for lateral movement along the axis of said spindle, means on said spindle for preventing said lateral Gil movement of said rocker arm, said means comprising two opposite sleeve shaped parts adapted to embrace said spindle, and a resilient clip engaging said parts and adapted to clamp them on said spindle removably.

3. In a valve actuating gear including an actuated member, an actuating member and a rocker arm having a hub portion and a contact portion adapted to be normally located intermediate the actuated and actuating members, a mounting for said rocker arm comprising a spindle on which said rocker arm hub portion is mounted for rocking movement and also for lateral movement along the axis of said spindle, means on said spindle for preventing said lateral movement 01' said rocker am, said means comprising two opposite sleeve shaped parts adapted to embrace said spindle, and a resilient clip engaging said parts and adapted to clamp them on said spindle removably, said clip having an intermediate grasping loop and limbs with diverging sloping free ends.

4. In a valve actuating gear including an actuated member, an actuating member and a rocker arm having a hub portion and a contact portion adapted to be normally located intermediate the actuated and actuating members, a mounting for said rocker arm comprising a spindle on which said rocker arm hub portion is mounted for rocking movement and also for lateral movement along the axis of said spindle, and a claspremovable transversely to said spindle, said clasp comprising two opposite parts adapted to embrace said spindle to hold said arm in normal position and interconnected by a resilient member.

ALESSANDRO TEBALDI. 

